/* $ID$ */

/*
* Copyright (c) 2011, Yury Y. Kuznetsov
* All rights reserved.
* 
* Redistribution and use in source and binary forms, with or without modification, 
* are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice, 
*   this list of conditions and the following disclaimer.
* o Redistributions in binary form must reproduce the above copyright notice, 
*   this list of conditions and the following disclaimer in the documentation 
*   and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
* SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY 
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "cgetopt.h"

const int BADCH = (int)'?';
const int BADARG = (int)':';
const char *EMSG = "";

Getopt::Getopt() 
	:
	place(EMSG),
	opterr(1),		/* if error message should be printed */
	optind(1),		/* index into parent argv vector */
	optopt(0),			/* character checked for validity */
	optreset(0),		/* reset getopt */
	optarg(0)		/* argument associated with option */
{
}

static const char *
_getprogname()
{
	return "";
}

/*
 * getopt --
 *	Parse argc/argv argument vector.
 */
int
Getopt::getopt(int nargc, char * const nargv[], const char *ostr)
{
	const char *oli;				/* option letter list index */

	if (optreset || *place == 0) {		/* update scanning pointer */
		optreset = 0;
		place = nargv[optind];
		if (optind >= nargc || *place++ != '-') {
			/* Argument is absent or is not an option */
			place = EMSG;
			return (-1);
		}
		optopt = *place++;
		if (optopt == '-' && *place == 0) {
			/* "--" => end of options */
			++optind;
			place = EMSG;
			return (-1);
		}
		if (optopt == 0) {
			/* Solitary '-', treat as a '-' option
			   if the program (eg su) is looking for it. */
			place = EMSG;
			if (strchr(ostr, '-') == NULL)
				return (-1);
			optopt = '-';
		}
	} else
		optopt = *place++;

	/* See if option letter is one the caller wanted... */
	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
		if (*place == 0)
			++optind;
		if (opterr && *ostr != ':')
			(void)fprintf(stderr,
			    "%s: illegal option -- %c\n", _getprogname(),
			    optopt);
		return (BADCH);
	}

	/* Does this option need an argument? */
	if (oli[1] != ':') {
		/* don't need argument */
		optarg = NULL;
		if (*place == 0)
			++optind;
	} else {
		/* Option-argument is either the rest of this argument or the
		   entire next argument. */
		if (*place)
			optarg = place;
		else if (nargc > ++optind)
			optarg = nargv[optind];
		else {
			/* option-argument absent */
			place = EMSG;
			if (*ostr == ':')
				return (BADARG);
			if (opterr)
				(void)fprintf(stderr,
				    "%s: option requires an argument -- %c\n",
				    _getprogname(), optopt);
			return (BADCH);
		}
		place = EMSG;
		++optind;
	}
	return (optopt);			/* return option letter */
}

// Local Variables:
// mode: c++
// c-basic-offset: 4
// tab-width: 4
// End:
